311 research outputs found

    Chronic copper poisoning in sheep: liver injury

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    Pathogenesis of liver injury in chronic copper poisoning of sheep was investigated using two experiments. Test sheep were dosed orally with a 0.2 % solution of CuSO4.5H2O at the rate of 10 ml/Kg body weight on five days of the week, until first day of the haemolytic crisis (HC). Liver samples were taken during the pre-haemolytic period and on the first or second day of the HC, liver changes were evaluated using trace element, histochemical, subcellular fractionation, ultrastructural and morphometric methods. Copper concentrations in liver samples increased at a steady linear rate of 10.35 μg/g liver wet weight per day; uptake of copper among hepatocytes, among Kupffer cells and between zones of liver lobules was unequal. Individual hepatocytes became packed with copper loaded lysosomes and underwent degeneration and necrosis. Excess copper in liver cells was sequestered by the lysosomes leading to linear increases in volume density, numerical density and mean volume during the pre-haemolytic period. On the first day of HC, numerical density reduced, volume density remained unchanged and the mean volume increased. Linear increase in liver copper concentration indicates that copper absorption from the gut; excretion into bile and release into sinusoids by hepatocytes occur at linear steady rates. Thus, copper homeostasis in sheep is different to that of the humans and rats. In hepatocytes packed with copper loaded lysosomes, synthesis of new lysosomes reduced, causing decreased uptake of excess copper leading to accumulation of ionic copper in the cytoplasm, resulting in the degeneration and necrosis of the hepatocytes.Jaliya Sarath Kumaratilak

    The brown adipocyte differentiation pathway in birds: An evolutionary road not taken

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    Background Thermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common white fat adipocytes by having numerous small lipid droplets rather than a single large one, elevated numbers of mitochondria, and mitochondrial expression of the nuclear gene UCP1, the uncoupler of oxidative phosphorylation responsible for non-shivering thermogenesis. Results We have identified in vitro inductive conditions in which mesenchymal cells isolated from the embryonic chicken limb bud differentiate into avian brown adipocyte-like cells (ABALCs) with the morphological and many of the biochemical properties of terminally differentiated brown adipocytes. Avian, and as we show here, lizard species lack the gene for UCP1, although it is present in amphibian and fish species. While ABALCs are therefore not functional brown adipocytes, they are generated by a developmental pathway virtually identical to brown fat differentiation in mammals: both the common adipogenic transcription factor peroxisome proliferator-activated receptor-γ (PPARγ), and a coactivator of that factor specific to brown fat differentiation in mammals, PGC1α, are elevated in expression, as are mitochondrial volume and DNA. Furthermore, ABALCs induction resulted in strong transcription from a transfected mouse UCP1 promoter. Conclusion These findings strongly suggest that the brown fat differentiation pathway evolved in a common ancestor of birds and mammals and its thermogenicity was lost in the avian lineage, with the degradation of UCP1, after it separated from the mammalian lineage. Since this event occurred no later than the saurian ancestor of birds and lizards, an implication of this is that dinosaurs had neither UCP1 nor canonically thermogenic brown fat.Nadejda V Mezentseva, Jaliya S Kumaratilake and Stuart A Newma

    Chronic Copper Poisoning in Sheep: Liver Injury

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    Quantifying asymmetry of anterior cerebral arteries as a predictor of anterior communicating artery complex aneurysm

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    ObjectivesThe aim of this study was to establish an anatomical index for early prediction of the risk of development of aneurysms in anterior communicating arterial complex (AcomAC). The asymmetric diameter of one anterior cerebral artery (ACA) to other could alter haemodynamics and may contribute to formation of aneurysms in AcomAC and be a reliable predictor of the risk of development of aneurysms.Design and settingThis is a retrospective, observational and quantitative study, which used cerebral computed tomography angiography (CCTA) scans in South Australia.ParticipantsCCTA scans of 166 adult patients of both sexes were studied.Main outcome measuresThe internal diameters of the proximal segments of ACAs (A1s) were measured. Position and presence or absence of aneurysms in AcomAC were determined. The ratio of A1 diameters was taken as a measure of A1 asymmetry.ResultsThe ratio of diameters of A1s correlated with the occurrence of AcomAC aneurysms. The risk of development of aneurysms in AcomAC was much greater (80%, OR=47.3) when one A1 segment’s radius was at least 50% larger (ie, 2.25 times cross-sectional area) than the other.ConclusionThe general information on asymmetric A1 has been published previously. The present findings have significant contribution since the A1s asymmetry ratios have been categorised in ascending order and matched with the presence of AcomAC aneurysms. The asymmetry ratio of the A1 is a good predictor for the development of AcomAC aneurysms. Reconstruction of the asymmetric A1 could be done if the technology gets advanced.</jats:sec

    Integral segmental bi-lateral renal arteries and unilateral renal veins in a cadaver: a new classification

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    Right and left additional single renal arteries and additional two right renal veins were observed in a female cadaver. Additional arteries arose from the abdominal aorta and entered kidney at inferior borders of renal hila. Additional renal veins exited the kidney at the mid-posterior and inferior borders of the hilum, and joined mid-posterior and lateral wall of inferior vena cava respectively. Variations in the structure and arrangements of main and additional renal vessels have been reported, but classifications or nomenclatures used to describe them varied markedly among publications. Therefore, established a classification to unify the future descriptions. According to the new classification, the normal renal vessels are referred to as main and segmental renal arteries and veins. Additional renal arteries and veins are identified as integral segmental arteries and veins respectively. If there is more than one such vessel, they will be identified numerically from the superior to inferior poles.Jaliya S Kumaratilake and Arthur Sanioti

    The Oral Health of a Group of 19th Century South Australian Settlers in Relation to Their General Health and Compared with That of Contemporaneous Samples

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    The aims of this study are to determine the oral health status of a rare sample of 19th-century migrant settlers to South Australia, how oral conditions may have influenced their general health, and how the oral health of this group compares with contemporaneous samples in Australia, New Zealand, and Britain. Dentitions of 18 adults and 22 subadults were investigated using non-destructive methods (micro-CT, macroscopic, radiographic). Extensive carious lesions were identified in seventeen adults and four subadults, and from this group one subadult and sixteen adults had antemortem tooth loss. Sixteen adults showed evidence of periodontal disease. Enamel hypoplastic (EH) defects were identified in fourteen adults and nine subadults. Many individuals with dental defects also had skeletal signs of comorbidities. South Australian individuals had the same percentage of carious lesions as the British sample (53%), more than other historic Australian samples, but less than a contemporary New Zealand sample. Over 50% of individuals from all the historic cemeteries had EH defects, suggesting systemic health insults during dental development were common during the 19th century. The overall oral health of the South Australian settlers was poor but, in some categories, (tooth wear, periapical abscess, periodontal disease), better than the other historic samples

    Variation of human hairiness: a possible adaptation to solar radiation and melanin

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    Many theories have been advanced to explain human hairlessness, however, there is no consensus. This study of 76 males observed that skin reflectance measuring skin colouration and melanin pigmentation correlated with hair size and follicle density. Individuals with a greater concentration of melanin within the superficial layer of the skin had a lower follicle density and smaller sizes of hairs. In contrast, individuals with a lower melanin concentration and lighter skin colour had a full range of hairiness. This leads to the suggestion that over the course of human evolution, high concentrations of melanin in consistently exposed to ultraviolet radiation areas developed first and that hair loss was a consequence of competition in the skin between melanin production and hair growth. Darker pigmented skin and lower follicle density are significantly correlated (R2=0.283; p<0.05). Individuals with darker skin had a mean of 4.91 follicles per cm2 whereas those with lighter skin reflectance had 11.20 follicles per cm2. This suggests that increased concentrations of melanin in the basal layer of the epidermis may limit hairiness by negatively influencing the skin's ability to produce hair.Amrita Dhugga, Maciej Henneberg, Jaliya Kumaratilak

    Gross anatomy of the gluteal and posterior thigh muscles in koalas based on their innervations

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    コアラのおしりを徹底解剖! --神経分布から筋を特定・前世紀以来の解剖記述不一致を解消--. 京都大学プレスリリース. 2022-09-22.Morphological and functional comparison of convergently-evolved traits in marsupials and eutherians is an important aspect of studying adaptive divergence in mammals. However, the anatomy of marsupials has been particularly difficult to evaluate for multiple reasons. First, previous studies on marsupial anatomy are often uniformly old and non-exhaustive. Second, muscle identification was historically based on muscle attachment sites, but attachment sites have since been declared insufficient for muscle identification due to extensive interspecific variation. For example, different names have been used for muscles that are now thought to be equivalent among several different species, which causes confusion. Therefore, descriptions of marsupial muscles have been inconsistent among previous studies, and their anatomical knowledge itself needs updating. In this study, the koala was selected as the representative marsupial, in part because koala locomotion may comprise primate (eutherian)-like and marsupial-like mechanics, making it an interesting phylogenetic group for studying adaptive divergence in mammals. Gross dissection of the lower limb muscles (the gluteal and the posterior thigh regions) was performed to permit precise muscle identification. We first resolved discrepancies among previous studies by identifying muscles according to their innervation; this recent, more reliable technique is based on the ontogenetic origin of the muscle, and it allows for comparison with other taxa (i.e., eutherians). We compared our findings with those of other marsupials and arboreal primates and identified traits common to both arboreal primates and marsupials as well as muscle morphological features unique to koalas

    Health effects of European colonization: An investigation of skeletal remains from 19th to early 20th century migrant settlers in South Australia

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    The British colony of South Australia, established in 1836, offered a fresh start to migrants hoping for a better life. A cohort of settlers buried in a section of St Mary’s Anglican Church Cemetery (1847–1927) allocated for government funded burials was investigated to determine their health, with a focus on skeletal manifestations associated with metabolic deficiencies. Findings of St Mary’s sample were compared with those published for contemporary skeletal samples from two British cemeteries, St Martin’s, Birmingham, and St Peter’s, Wolverhampton, to explore similarities and differences. To investigate the changing economic background of the St Mary’s cohort, which may have influenced the location of their burial within the cemetery, the number and demographic profile of government funded burials and those in privately funded leased plots were compared. The study sample consisted of the skeletal remains of 65 individuals (20 adults, 45 subadults) from St Mary’s Cemetery ‘free ground’ section. The bones and teeth of individuals in this cohort showed evidence of pathological manifestations, including areas of abnormal porosity in bone cortices in 9 adults and 12 subadults and flaring of metaphyses (one subadult) and costochondral junctions of the ribs (one subadult). Porous lesions of orbital roof bones (Types 3 to 4) were seen on three subadults. Macroscopic examination of teeth identified enamel hypoplastic defects and micro-CT scans showed areas of interglobular dentine. Comparison of St Mary’s findings with the British samples revealed that prevalences of manifestations associated with vitamin C deficiency were higher at St Mary’s and manifestations associated with vitamin D deficiency were lower respectively. The location of burial pattern at St Mary’s Cemetery, from the mid-1840s to1860s, showed differences in the economic status of migrants. This pattern changed from the 1870s, which reflected improvements in the local economy and the economic recovery of the colony

    Dietary fats and oils: some evolutionary and historical perspectives concerning edible lipids for human consumption

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    Consumption of fats and oils in the ancient world was examined as a window to human nutritional needs and compared with lipid usage in the modern world, post-1900. In earlier periods, the natural and only source of edible fats and oils came from both animals and plants. These fats and oils played a vital role in the evolution of the human body structure, supporting many biochemical functions. Artifacts from prehistoric periods and the ancient world had indicated that humans were evolutionarily adapted to consume saturated lipids. They also consumed unsaturated fats and oils extracted from animals and plants, now identified as omega-3 to omega-6 in the fatty acid ratio of 1:1, commonly derived from naturally consumed unprocessed products and food sources. These fats and oils assisted in providing the ingredients for the building up of cells and maintaining their structural integrity in tissues, including the brain and other important internal organs, as well as providing energy for many biochemical processes in the body. The double bonds distributed throughout fatty acid carbon chains are a characteristic of unsaturated vegetable oils. They are more structurally diverse in polyunsaturated fats and oils with the greater preponderance for carbon-to-carbon double bonds distributed in the carbon chains. These double bonds are susceptible to generating free radicals. This article considers potential problems that proponents of the prevailing diet-heart cholesterol paradigm of the past 60 years may have neglected. It also presents the possible consequences of abandoning the evolutionarily inherited foods containing extracted natural saturated and monounsaturated fats and oils. Furthermore, the article addresses the contribution of docosahexaenoic and eicosapentaenoic acids to immunity and the possible connection of excess consumption of omega-6 fatty acid to the marked rise in obesity and other non-communicable diseases in modern civilization.Dante Roccisano, Jaliya Kumaratilake, Arthur Saniotis, Maciej Henneber
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